The Effect of Route of Inoculation and Challenge Dosage on Riemerella anatipestifer Infection in Pekin Ducks (Anas platyrhynchos)

Abstract

Riemerella anatipestifer is a gram-negative bacteria that can cause disease in a wide variety of wild and domesticated birds, especially waterfowl. The infection can be peracute, acute, or chronic. Although various routes of transmission have been proposed, to date, there is little information on the effects of route of transmission and challenge dosage on R. anatipestifer infection. Hence, the objective of this study was to determine the effect of route of inoculation and challenge dosage on R. anatipestifer infection and pathology. To achieve this objective, one hundred forty-seven 14-day-old white Pekin ducks (Anas platyrhynchos) were equally divided into 13 experimental groups (12 challenge and 1 control group). Each challenge group had 11 ducks. The control group had 15 ducks. Four routes of inoculation were evaluated (intranasal, oral, subcutaneous, and intravenous). Three dosage levels were evaluated for each inoculation route (10(2), 10(4), and 106 colony forming units [CFU]/ml). At the 106 CFU/ml dosage level, mortality was most associated with the subcutaneous (91%) and intravenous (82%) routes, followed by the nasal (18%) and oral (9%) routes. A unique pathologic lesion was found in the bursa of Fabricius and spleen of affected birds. Within the spleen and bursa of Fabricius, there were varying degrees of lymphoid depletion and necrosis within the cortical and medullary regions. These pathologic lesions have not been previously reported in ducks with R. anatipestifer infection.

Identification of Ribonuclease Z Gene from an Outbreak of Riemerella anatipestifer Infection in Ducks of Bangladesh

“…The result revealed maximum morbidity and mortality during June to July at the 8-10 weeks of age group where, earlier report suggested R. anatipestifer infection occur during summer [9] and 7-10 weeks of age of ducks [3,7,8]. Nervous signs observed in this study are suggestive to infection with R. anatipestifer [10,17,18]. At necropsy, grey color necrotic foci onto the surface of swollen, congested and hemorrhagic liver was characteristics and typical lesions for infection with either R. anatipestifer [8,19,20] or P. …”

Prevalence and molecular characterization of chloramphenicol resistance inRiemerella anatipestiferisolated from ducks and geese in Taiwan

“…It is the causative agent of duck septicaemia (Segers et al, 1993), a contagious disease of domestic ducks, turkeys, and various other bird species. Duck septicaemia is a serious disease that has caused major economic losses for many duck farmers (Ryll et al, 2001;Sarver et al, 2005). Clinical signs include fibrinous pericarditis, perihepatitis, and airsacculitis.…”

Identification ofRiemerella anatipestifergenes differentially expressed in infected duck livers by the selective capture of transcribed sequences technique

“…anatipestifer is an avian pathogen of ducks and turkeys, and it is a major economic burden in the duck industry worldwide (Huang et al, 1999;Ryll et al, 2001;Pathanasophon et al, 2002;Sarver et al, 2002;Cheng et al, 2003). Limited information about the molecular basis of the pathogenesis is available for this organism, and so far only two potential bacterial virulence or virulence-associated gene have been identified (Weng et al, 1999;Crasta et al, 2002).…”

“…The latter is a contagious disease for domestic ducks, turkeys, and various other birds, and the disease can occur in an acute or chronic form of septicaemia, characterized by fibrinous pericarditis, perihepatitis, and airsacculitis. R. anatipestifer infection accounts for major economic losses for duck farmers (Sandhu & Rimler, 1997;Ryll et al, 2001;Sarver et al, 2002), especially in China and Southeastern Asia countries (Huang et al, 1999;Pathanasophon et al, 2002;Cheng et al, 2003). Such an infection causes high mortality and morbidity rates, typically ranging from 10% to 30% (Guo et al, 1982;Loh et al, 1992;Subramanism et al, 1997).…”